corbin14e_ch13_PPT

corbin14e_ch13_PPT - Presentation Package for Concepts of...

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Unformatted text preview: Presentation Package for Concepts of Physical Fitness 14e Concepts Section V: Concept 13 Possessing an optimal amount of body fat Possessing contributes to health and wellness. contributes Body Body Composition Composition All rights reserved Understanding & Interpreting Body Understanding Composition Measures Composition • Component of health-related fitness & a Component component of metabolic fitness. component • Standards have been established for Standards healthy levels of body fatness (see next slide) slide) • Health standards have been established Health for the Body Mass Index. for • Assessing body weight too frequently Assessing can result in making false assumptions about body composition changes. about 2 Concepts of Physical Fitness 14e 3 Concepts of Physical Fitness 14e Methods Used to Assess Body Methods Composition Composition • • • • • DXA Underwater Weighing Bod Pod Skinfold technique Other 4 Concepts of Physical Fitness 14e Dual-energy Absorptiometry (DXA) • “Gold Standard” measure of Gold body composition. body • Provides whole body Provides measurements of body fatness as well as amounts stored in different parts of the body. different • Highly accurate measure of body Highly composition for research and a criterion measure that has been used to validate other, more practical measures of body composition. composition. 5 Concepts of Physical Fitness 14e Click for more info more Underwater Weighing A person is weighed in person air and under water, and the difference in weight is used to assess the levels of body fatness. levels Body fat provides more Body buoyancy, so a fatter person weighs less (on a relative basis) than a lean person. lean 6 C Web13-3 foroncepts ofon underwater weighing info Physical Fitness 14e Bod Pod • Uses the same principles as underwater Uses weighing, but relies on air displacement to assess body composition. • Evidence suggests that it provides an Evidence acceptable alternative to underwater weighing and is particularly useful for special populations (obese older people and the physically challenged). and 7 Concepts of Physical Fitness 14e Skinfold Technique Layers of Layers subcutaneous fat are measured at different sites of body body to estimate total to body fat levels body Cross sectional view 8 Concepts of Physical Fitness 14e Benefits of Skinfold Technique • Skinfold measurements are the Skinfold preferred, practical method of assessing body fatness. body • Fairly accurate • Easy to perform • Inexpensive Lab 13a info 9 Concepts of Physical Fitness 14e Common Skinfold Sites 7 site procedure site Chest Chest Axilla Tricep Subscapular Abdomen Supraillium Thigh Thigh Validation statistics on 3 site test: Validation - r = .97 with 7 site procedure .97 - R2 = .80 with underwater weighing 10 Jackson and Pollack Jackson Males Female Chest Abdomen Thigh Triceps Supraillium Thigh Alternative Sites (Males & Females) Tricep Abdomen Calf Web13-04 Concepts of Physical Fitness 14e Research Quality Research Skinfold Calipers Skinfold Harpenden Calipers 11 Lange Calipers Concepts of Physical Fitness 14e Other Body Composition Other Assessments Assessments • • • • Bioelectrical Impedance Infra-Red Spectroscopy Ultrasound Imaging Techniques Click to see more info on all more techniques techniques 12 Concepts of Physical Fitness 14e Lab 13b info Anthropometric Anthropometric Measurements Measurements • Body Mass Index (BMI) More info • Waist to Hip Ratio (WHR) More info • Circumference measures More info 13 Concepts of Physical Fitness 14e Body Composition Assessment Implications of Results • Values are estimates (+/- 2-3% at best) • Values are personal and confidential Proper uses of results: - Serve as baseline data for repeated testing - Provide motivation for goal setting - Provide awareness about health risks 14 Concepts of Physical Fitness 14e Health Risks Associated with Health Being Overweight Being • • • • • • Coronary heart disease Hypertension Hypercholesterolemia Diabetes Premature death Physical fitness provides protection Physical from the health risks of obesity. from 15 Concepts of Physical Fitness 14e There are also health risks associated with being too thin! Click for more info on fat info deposition Regional Fat Deposition • Abdominal body fat poses greater health Abdominal risks than fat stored in other areas risks • Males store more fat Males centrally and have increased health risks associated with body fatness with 16 Male (apple) Male Higher health risk Female (pear) Female Lower health risk Concepts of Physical Fitness 14e Health Risks Associated with Excessively Low Body Fatness • • • • • • Anorexia Nervosa Bulimia Anorexia Athletica Female Athlete Triad Muscle Dysmorphia (males) Fear of Obesity 17 Concepts of Physical Fitness 14e The Origin of Fatness Lab 13c info • Obesity is a multifactorial disease that is Obesity influenced by both genetics and the environment. environment. • Body weight is regulated and maintained Body through complex regulatory processes. through – Set-point • Fatness early in life leads to adult fatness. • Changes in basal metabolic rate can be the Changes cause of obesity. cause • “Creeping Obesity” (see next slide) Creeping (see 18 Concepts of Physical Fitness 14e 19 Concepts of Physical Fitness 14e Relationship Between PA & Body Relationship Composition Composition • Combination of regular PA and dietary regular PA and dietary restriction is the most effective means of restriction most effective means losing body fat. losing body fat • PA that can be sustained for relatively long PA periods is considered the most effective for losing body fat. losing • Strength training can be effective in Strength maintaining a desirable body composition. maintaining • Regular PA is critical for building and Regular maintaining bone health. maintaining 20 Concepts of Physical Fitness 14e Target Zone - Body Fat Reduction Table 3, p. 285 Physical Activity Activity Daily moderate PA; Daily 3-6 days/wk vigorous PA vigorous Slow, low-intensity Slow, that results in ≤1-2 lbs/week of fat loss lbs/week 30-60 minutes 21 Concepts of Physical Fitness 14e Diet Consistently Consistently and daily and Modest Modest caloric restriction restriction Moderate Moderate meals meals Obesity Trends* Among U.S. Adults BRFSS, 1990, 1995, 2005 (*BMI ≥ 30, or about 30 lbs overweight for 5’4” person) 1995 1990 2005 No Data 25%–29% <10% ≥30% 22 10%–14% 15%–19% Concepts of Physical Fitness 14e 20%–24% Web Links • Behavioral Risk Factor Surveillance Behavioral System (BRFSS) Interactive Web Page (BRFSS) http://www.cdc.gov/brfss/ 23 Concepts of Physical Fitness 14e Summary • Obesity is prevalent in society. • Need to find ways to maintain optimal Need body composition. body • Use assessments to determine body Use composition and make the necessary healthy changes to physical activity and diet. and 24 Concepts of Physical Fitness 14e Web Resources Online Learning Center “On the Web” pages for Concept On pages 25 Concepts of Physical Fitness 14e Supplemental Graphics Graphics •Lab Information •Detail on BMI calculations •Graphics on Obesity Trends Lab 13a Information Evaluating Body Composition - Skinfolds • The purpose of this lab is to The evaluate body composition with the skinfold assessment. with • Comparisons will be made Comparisons between different procedures and testers to learn about the accuracy of the tests. accuracy 27 Concepts of Physical Fitness 14e Lab 13a Information Skinfold Technique Return to presentation presentation • Measurement Technique: – Mark site with marker – Pinch fold above and below Pinch mark with left and right hand mark – Measure fold with caliper Measure using the right hand using • Scoring Procedure: – Sum skinfolds from the 3 sites – Look up percent body fat value from chart in the book 28 Concepts of Physical Fitness 14e Lab 13b Information Evaluating Body Composition – Height, Weight, and Evaluating Circumference Measures Circumference • The purpose of this lab is to The evaluate body composition with some anthropometric assessments assessments – Height/Weight – Body Mass Index – Waist to Hip Ratio 29 Concepts of Physical Fitness 14e Lab 13b Information BMI Measurement Technique BMI Return to Return presentation presentation • • • • Convert weight to kilograms (2.2 kg/lb.) Convert height to meters (.0254 m/in) Square the height in meters Divide the squared height value into the Divide weight value weight BMI = Wt (kg) / Ht2 (m) See Web13-06 for BMI calculators 30 Concepts of Physical Fitness 14e Lab 13b Information WHR Measurement Technique WHR • Waist: Measure at the "natural waist" (smallest circumference) or at the level of the umbilicus level Return to Return presentation presentation • Hip: Measure at the maximum circumference of the buttocks circumference Divide the hip measurement into the Divide waist measurement to obtain the WHR waist 31 Concepts of Physical Fitness 14e Sample BMI Values Return to Return presentation presentation This chart reveals how BMI values change for a This hypothetical 6 foot tall person of different body weights hypothetical HT (in.) See Web1306 for BMI 06 calculators calculators WT (lb.) BMI 150 180 190 200 Concepts of Physical Fitness 14e 72 72 72 72 32 21 25 26 28 Definitions of Overweight (Based on BMI values) (Based Return to Return presentation presentation • BMI accounts for differences in frame size BMI better than height weight tables. BMI = Wt (kg) / Ht2 (m) BMI Problem: BMI does not take muscles mass into account Standards: muscles – Overweight: > 25 25 – Obesity: > 30 – Severe obesity > 40 Web13-1 for more information on standards 33 Concepts of Physical Fitness 14e Lab 13c Information Determining Your Daily Energy Expenditure • Estimate your basal metabolism. Return to Return presentation presentation • First determine the number of minutes you sleep. • Monitor your activity expenditure for 1 day. Record Monitor the number of 5-, 15-, and 30-minute blocks of time you perform each of the different types of physical activities (e.g., if an activity lasted 20 minutes, you would use one 15-minute block and one 5-minute block). Be sure to distinguish between moderate (Mod) and vigorous (Vig) intensity in your logging. (Mod) • Discuss your daily caloric expenditure. In addition, Discuss comment on whether you think you should modify your daily caloric expenditure for any reason. your 34 Concepts of Physical Fitness 14e Regional Fat Deposition Visceral Fat • Visceral body fat poses greater health Visceral risks because this fat is more labile and has greater access to the circulation. has • The accumulation of visceral body fat is The typical of the android (male) fat pattern typical – males: visceral accounts for 10-35% of total fat – females: visceral accounts for 8-13%of total fat 35 Concepts of Physical Fitness 14e Abdominal Body Fat Relationships with CHD Risks • Abdominal obesity predicts CHD risk Abdominal independent of BMI, smoking, cholesterol and hypertension. and (Kannel et al., J. Clin Epid., 44, 183-190, 1991). • Abdominal obesity predicts CHD risk Abdominal independent of total body fatness. independent (Larsson et al. ,Appetite, 13, 37-44, 1989). (Larsson • Abdominal obesity statisticallly accounts for Abdominal difference in CHD rates between men and women. (Larsson et al., Am. J. Epi., 135: 266-273, 1992). women. (Larsson 36 Concepts of Physical Fitness 14e Abdominal Body Fat Relationships with other risk factors • Abdominal obesity is strongly influenced by genetics Abdominal similar gain among twins (r=.72). (Bouchard, NEJM, 322, 1477-1482, 1990). (Bouchard, • Abdominal obesity is greater in smokers than nonsmokers due to the presence of androgens smokers (Barrett-Conner, Ann. Int. Med. 111, 783-787, 1989). (Barrett-Conner, • Abdominal body fat is preferentially lost during a Abdominal physical activity program physical (Kohrt, J. Gerontology, 47: M99-M105, 1992) 37 Concepts of Physical Fitness 14e Waist to Hip Ratio (WHR) (WHR) Return to Return presentation presentation • Waist to Hip Ratio is an effective way Waist to examine regional fat distribution. to HEALTH RISK High Risk Moderate Risk Low Risk 38 MEN > 1.0 .90 -1.0 < .90 .90 Concepts of Physical Fitness 14e WOMEN WOMEN > .85 .85 .80-.85 < .80 .80 Underwater Weighing Measurement issues – Density of lean tissue = 1.1 g/cc – Density of fat tissue = .9 g/cc Return to Return presentation presentation • Based on body density calculations • Sources of error – Residual lung volume – Bone density varies by age, ethnicity and activity Bone level level • General conclusions – Gold standard measure (1-2% error) – Impractical for most applications 39 Concepts of Physical Fitness 14e Bioelectric Impedance (Measurement Issues) • Based on resistance to current flow – Lean tissue has more water - less resistance – Fat tissue has less water - more resistance Return to Return presentation presentation • Sources of error – Temperature – Hydration status • General conclusions – Overestimates lean / underestimates obese – Practical, but expensive, measure for general Practical, population population 40 Concepts of Physical Fitness 14e Infrared Spectroscopy (Measurement Issues) • Based on differential absorbance rates – Lean tissue has a different energy absorption Lean and reflectance pattern than fat tissue and Return to Return presentation presentation • Sources of error – Validity of absorbance readings is questionable! • General findings – NOT a valid measure! 41 Concepts of Physical Fitness 14e Ultrasound (Measurement Issues) • Based on reflection of sound • Sources of error Return to Return presentation presentation – Fat content increases the time is required Fat for sound to reflect off of bone and muscle. – Representative sites for measurement – Measurement error – Highly accurate measure of body fat Highly especially for obese especially – Expensive and not practical for most Expensive applications applications 42 Concepts of Physical Fitness 14e • General conclusions Imaging Techniques (Measurement Issues) Return to Return presentation presentation • Based on imaging of body tissues – Based on cross sectional area measures Based calculated at different levels of the body calculated • Sources of error – Representative sites for measurement – Measurement error • General conclusions – Very precise measure of body composition – Expensive and not practical measure for most uses 43 Concepts of Physical Fitness 14e Circumferences (Measurement Technique) (Measurement Return to Return presentation presentation • Based on circumference measures – sample prediction equation: % fat = - 47.372 + (.579 x abdomen) + (.252 x hip) + fat (.214 x iliac) + (.356 x BW) (.214 – Location of sites – Inability to distinguish fat and muscle – Provides reasonable estimate of body fat – Not as accurate as skinfold and takes same time 44 Concepts of Physical Fitness 14e • Sources of error • General conclusions ...
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